Silencers for suction rolls



May 25, 1965 R. B. wlGGlNs ETAL 3,185,618

SILENCERS FOR SUCTION ROLLS Filed Jan. 22, 1962 INVENTORS ROBERT B.WIGGINS. ARNOLU C.ROESER.

ATTORNEYS.

United States Patent M 3,185,618 SILENCERS FOR SUCTION ROLLS Robert B. Wiggins and Arnold C. Roeser, Green Bay, Wis., assignors to Fort Howard Paper Company, Green Bay, Wis., a corporation of Wisconsin Filed Jan. 22, 1962, Ser. No. 167,806 Claims. (Cl. 162-371) This invention relates to improvements in silencers for suction rolls.

In the manufacture of paper it is conventional practice to pass the stock on a screen over suction boxes which are on the inside of rotating drums or shells. The drums are perforated so that the suction is transmitted to the stock through these perforations. When these perforations pass beyond the vacuum zone of the suction box, air suddenly ows into the holes. This produces the highpitched, whistling noise which is commonly heard in a paper-making plant.

Various attempts have in the past been made to reduce this noise, such as the use of grooved sealing strips or combs which are intended to give a gradual relief for the air so that the atmospheric air will not rush into the l holes suddenly. These devices are effective for a relatively short time only because, after suction rolls have been used, they tend to ll with paper bers, slime, sludge,

or other device is in close contact with the rotating shell land, hence, tends to wear due to the abrasive action. As

this wear continues, the silencer loses its effectiveness.

It is a general object of the present invention to prot vide an improved silencing device which is self-cleaning and which tends to maintain the inner surface of the shell clean to eliminate the abrasive action of grit or the like.

A further object of the invention is to provide an improved silencer which controls the amount of air which rushes into the holes of the shell in a very eective man- A more specific object of the invention is to provide an improved silencer in the form of brushes which contact the innerrside of the shell against the inner ends of the holes so that the bristles of the brushes are constantly kept working to keep the inside surface of the shell clean and to keep the brushes themselves clean.

A further object of the invention is to provide a silencer y embodying brushes on opposite sides of a water box whereby there is a constant overflow of water from the box through the set of brushes which is farthest from the vacuum chamber to thereby keep the brushes clean, said water in the water box also serving to perform a sounddeadening function.

A further object of the invention is to provide a silencer device embodying novel brushes wherein the latter are so mounted that they may be readily replaced when required. l t

With the above and other objects in view, the invention consists of the improved silencer for suction rolls, and all of its parts and combinations, as set forth in the claims, and all equivalents thereof.' In the accompanying drawings, illustrating one complete embodiment of the preferred form of the invention, in which the same reference numerals designate the same parts in all of the views:

FIG. l is a fragmentary transverse Yvertical sectional view through a suction roll;

3,185,618 Patented May 25, 1965 ICC length of the core of the suction roll, the outer shell being removed; and

FIG. 3 is a fragmentary sectional view taken approximately on the line 3-3 of FIG. l.

Referring more particularly to the drawing, the numeral 10 designates the core of a suction roll, said core including a suction box 11 having an open area 12 adjacent the rotating outer shell 13, whereby water may be removed from stock supported on the shell 13 through holes 14 in the shell. Extending longitudinally on each side of the suction box are the conventional seals 15.

As a novel feature of the present invention, there is supported on the left hand side of the suction box an elongated water box 16 having walls 17 and 18 and closed ends. Supported on the inner side of the wall 17, through a series of detachably bolted clamps 19, is a set of brushes which are designated generally by the numeral 20. The brushes comprise suitable holders 21 for upstanding bristles 22, and the latter may be formed of nylon or other suitable material. The brushes are of any convenient length, and a plurality of them are mounted on each side of the water box in endwise, abutting relationship, the ends of two brush backs being shown as abutting at 23 in FIG. 3. Another set of brushes 20 is clamped to the wall 18 by clamps 24, as shown in FIGS. 1 and 2.

It should be noted that as the brushes become worn the bolts of the clamps 19 and 24 may beloosened and the brushes raised upwardly and reclamped. On the right hand side of FIG. 1 the brushes are shown in a maximum raised position and on the left hand side of FIG. 1 they are shown in a lowered position before wear has occurred. After the bristles have become worn excessively, whichis usually after about six months of operation, the brushes may be readily removed from the clamps and replaced.

In use of the device, with the shell 13 rotating in the direction indicated by the arrow in FIG. 1, as a hole 14 FIG. 2 is a fragmentary perspective view showing the passes the left hand seal 15 of the suction box it almost immediately arrives over bristles of the adjacent set of brushes. These bristles spread slightly so that there is a small .amount of space between bristles, which allows a gradual equalization of air pressure or a gradual inrush of air into the holes 14 to thereby substantially reduce the amount of whistling noise. Additional air is allowed to enter as the holes pass the next set of brushes. Thus the sudden inrush of air which normally causes excessive noise is prevented.

With prior types of silencers accumulations of paper ber, slime and sludge sooner or later lill up grooves or other gradual relief devices. With the present invention the brushes have bristle ends in engagement with the lower or inner ends of the holes 14, and these holes keep the bristles working so that the bristles clear themselves of sludge or the like so they do not become clogged. In addition, the bristles act as cleaning brushes on the inner side of the shell to keep the shell clean. Thus excessive wear ordinarily caused by foreign matter building up on the inner side of the shell is prevented. This is one of the problems connected with the use of silencers as heretofore proposed. Y f

In addition tothe above, water from the under side of the shell, which is deposited there by the usual interior suction roll showers'(not shown), gradually builds up in the water box 16, as at 25, to approximately the level shown in FIG. 1. This water constantly overflows adjacent the top of the wall 18 of the Water box, passing through the bristles of the left hand set of brushes to keep the bristles clean. In addition, the water in the box 16 produces a sound-deadening effect.

As before mentioned, the c1amps19 and 24 permit adjustment of the brushes toward or away from the under side of the shell to obtain the most effective engagement, and Said clamps also permit readjustment for the purpose of taking up wear. When required, usually after about six months of use, the detachable clamps permit complete,

Y easy replacement of the brushes.

It is to be understood that `the present invention is not to be limited to the exact details shown and described, for

" obvious modications will occur to persons skilled in leaving edge of the suction box axially of the roll and having outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes to control the admission of air to the holes after they leave the suction zone to thereby minimize noise, Vsaid bristles being of such length that they are kept working by the rotating shell.

2. A silencer for suction rolls of the type including a rotatable shell havingradially extending holes and including a stationary suction box having a suction zone cooperable with the inner periphery of the shell as the latter is rotated comprising an elongated box extending along vthe leaving edge of the suction box, and brush means supported on said elongated box and extending axially of the roll and having outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes to control the admission of air to the holes after they leave the suction zone to thereby minimize noise, said bristles being of such length that they are kept working by the rotating shell.

3. A silencer for suction rolls of the type including a rotatable shell having radially extending holes and including a stationary suction box having a suction zone cooperable with the inner periphery of the shell as the latter is rotated comprising an elongated box extending along the leaving edge ofthe suction box and having circumferentially spaced sides which extend axially of the roll, narrow brush means supported by at least one side of said elongated box for adjustment toward and away from the roll andhaving outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes to control the admissionof air to the holes after they leave the suction box, said bristles being of such length that they are kept working by the rotating shell.

4. A silencer for suction rolls of the type including a rotatable shell having radially extending holes and including a stationary suction box having a suction zone cooperable with the inner periphery of the shell as the latter is rotated comprising an elongated b'ox extending along the leaving edge of the suction box and having circumferentially spaced sides which extend axially of the roll, narrow brush means supported in circumferentially spaced condition by both sides of said elongated box and having outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes to control the admission of air to the holes after they leave the suction box, said bristles being of such length that they are kept working by the rotating shell.

5. YIn a silencer for suction rolls of the type including a rotatable shell having radially extending holes and including a stationary suction box having a suction Zone cooperable with the inner periphery of the shell as the latter is rotated, an elongated Water box extending along the leaving edge of the suction box and forming a trough in which water is collected and having two spaced sides extending axially of the roll, one of which is adjacent the suction box and the top edge of the other side being lower than the top edge of the gtirst-mentioned side so that water in the Water box will overtlow said lower side, and brush means supported by said lower side of said water box and extending axially of the roll and having bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes, said brush means being positioned so that it is continuously cleaned by water overflowing from the water box.

6. A silencer for suction rolls of the type including a rotatable shell having radially extending holes andincluding a stationary suction box having a suction zone cooperable with the inner periphery of the shell as the latter is rotated comprising an elongated water box extending along the leaving edge of the suction box and forming a trough in which water is collected, and brush means supported by said water box and extending axially of the roll and having outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes to control the admission of the air to the holes after they leave the suction zone, said bristles being of such length that they are kept working by the rotating shell.

7. A silencer for suction rolls of the type including a rotatable shell having radially extending holes and including a stationary suction box having a suction .zone cooperable with the inner periphery of the shell as the latter is rotated comprising an elongated water box extending along the leaving edge of the suction box and having spaced sides and forming a trough in which water is collected, and narrow brush means supported in circumferentially spaced condition by thesides of said water box and extending axially of the roll and having outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes to control the admission of the air to the holes after they leave the suction zone.

8. A silencer for suction rolls of the type including a rotatable shell having radially extending holes'and including a stationary suction box having a suction zone cooperable With the inner periphery of the shell as the latter is rotated comprising an elongated water box extending along the leaving edge of the suction box and having a first side near the suction box vand a second side spaced circumferentially therefrom, and said box forming a reservoir for water, and said second side being lower than said iirst side so that water will overflow the top edge of said second side, and narrow brush means supported in circumferentially spaced condition by both sides of said box and extending axially of the roll and having outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the under sides of the holes to control the admission of the air to the holes after they leave the suction zone, said brush means on said second side being positioned so that it is continuously cleaned by water overilowing the top edge of said low side of the water box.

9. A silencer for suction rolls of the type including a rotatable shell having radially extending holes and including a stationary suction box having a suction zone Vcooperable with the inner periphery of the shell as the latter is rotated comprising an elongated wall extending along the leaving edge of the suction box axially of the roll, narrow brushes extending along said wall and having outwardly projecting bristles positioned so that they wipe the inner periphery of the shell against the inner ends of the holes Ato control the admission of air to the holes after they leave the suction zone, and clamps for adjustably holding the brushes in position against said wall,

' whereby the eiective length of the bristles may be adalong the leaving edge of the suction box and having cii- 2,877,694 3/59 Thiessen 162-369 cumferentially spaced sides which extend axially of the 2,975,753 3/61 Hayes 118-49 roll, spaced brushes extending along said sides and having 2,989,026 6/ 61 Gardner et a1 118-49 outwardly projecting bristles positioned so that they Wipe the inner periphery of the shell against the inner ends of 5 FOREIGN PATENTS the holes to control the admission of air to the holes after they leave the suction zone, said bristles being of such 336916 3/61 Germany' length that they are kept Working by the rotating shell, and clamps for detachably holding the brushes in posii OTHER REFERFNCES tion against Said Sides. 10 Noise Abatement in the Machine Room, Parts 1-4,

Pulp and Paper Magazine of Canada 56, 8 pages, 104- Referellces Clted by the Examiner 11g; 56J 12 pages, 114 119.

UNITED STATES PATENTS 2,107,812 2/38 B erry et al 162 371 DONALL H. SYLVESTER, Primary Examiner. 2,857,823 10/58 Thiessen 162-369 15 RICHARD D. NEVIUS, Examiner. 

1. A SILENCER FOR SUCTION ROLLS OF THE TYPE INCLUDING A ROTATABLE SHELL HAVING RADIALLY EXTENDING HOLES AND INCLUDING A STATIONARY SUCTION BOX HAVING A SUCTION ZONE COOPERABLE WITH THE INNER PERIPHERY OF THE SHELL AS THE LATTER IS ROTATED COMPRISING BRUSH MEANS EXTENDING ALONG THE LEAVING EDGE OF THE SUCTION BOX AXIALLY OF THE ROLL AND HAVING OUTWARDLY PROJECTING BRISTLES POSITIONED SO THAT THEY WIPE THE INNER PERIPHERY OF THE SHELL AGAINST THE INNER ENDS OF THE HOLES TO CONTROL THE ADMISSION OF AIR TO THE HOLES AFTER THEY LEAVE THE SUCTION ZONE TO THEREBY MINIMIZE NOISE, SAID BRISTLES BEING OF SUCH LENGTH THAT THEY ARE KEPT WORKING BY THE ROTATING SHELL. 